Efficient ID-based Threshold Signature in P2P and MANETs

Threshold cryptography distributes the ability to provide a cryptographic service such as decryption or signing. It is an ideal choice to provide security services, such as authentication and access control, in MANETs or P2P systems. The paper proposes an ID-based threshold signature scheme, which has three attractive properties: (1) The user's co-signing key and signature share are all verifiable, which make the scheme robust. (2) The signature share psi is constant and has small size; it does not lengthen with the increase of the group members. (3) The process of generating signature share psi is non-interactive, so it does not require a synchronous communications network. So the scheme can be efficiently used in providing security set-vices in MANETs.